This invention relates to fluid evaporation devices and more specifically to a device for increasing the evaporation of fluids contained in large pits associated with well drilling operations and the production of oil and gas. The pits are known as "mud pits" of the barrow-type having earthen sides and containing a large quantity of water, e.g., 100,000 gallons or more from sources such as rain, washdown and from drilling mud used to lubricate the well drill bits.
The pits are continuously filling up from the aforementioned sources necessitating the collected water being frequently disposed of. Heretofore, this disposal has been accomplished by several methods which have not proved satisfactory either because of the design limitations of the equipment utilized, the high cost to effectively disposed of each gallon of water, or both. One solution was to spray the water thirty to forty feet into the air in the hopes that the spray would be carried out of the area by the wind. This was found to be no more satisfactory than to transport the water to another location at a high cost and dump it on the ground.
Another solution of the prior art was to use a solid core nozzle to dispense the water into a sufficiently fine spray to get enough surface contact area exposed to the atmosphere to thereby increase evaporation. These solid core nozzles have not been found effective for a number of reasons, one of which is the poor contact area of the droplets formed which is available for drying and evaporation. There is a very high percentage of droplets formed in the spray from the type of nozzle that are large and concentrated in the center of the spray which do not evaporate and merely return to the surface of the water. In addition, the area between the core and the sides of the opening is small which results in frequent clogging, thus rendering the nozzle useless. In addition, this area is frequently enlarged due to the abrasive action of contaminants often found in the water which act on the surface of the core and the sides of the opening thereby substantially reducing the efficiency of the nozzle. Other constriction-type nozzles that produce a fine mist spray have also not proved satisfactory because the exposure of the mist droplets is limited by the outside area of the mist or fog envelope. These constriction-type envelopes also clog and wear out very rapidly.
Applicant has discovered that if a nozzle is used having a hollow core rather than a solid core, the droplet size distribution is more homogeneous for equal flow rates and pressure. The hollow core nozzle produces a spray cone having a hollow core or center of air which results from liquid rotation in the nozzle itself. The smaller, more homogeneous, droplets with their greater combined surface area for air contact result in a higher rate of evaporation. A typical hollow core-type nozzle is disclosed in U.S. Pat. No. 3,326,473, the contents of which is specifically incorporated herein by reference.
The use of a plurality of such hollow core nozzles in combination with the collection chamber and flotation members of the present invention result in a unique and novel device capable of floating on the surface of the water in a mud pit and effectively evaporate into the atmosphere large quantities of water pumped thereto. In addition, because the discharge orifice of the nozzle is open, i.e., does not have a solid core, it is not susceptible to rapid wear or clogging by the buildup of particulate matter in the water. The collection chamber serves as a header to help equalize the pressure of the fluid exiting the nozzle as well as a place where a large amount of the particulate matter in the water can settle out and not be forced through the nozzle orifices.
Previously used spray-forming devices having utilized submerged pumps as an integral part of the evaporation assembly. Submerged pumps have been found to be subject to frequent failure which necessitates the removal of the spray apparatus from the mud pit in order to repair the pump. Further, submerged pumps on floating spray devices are generally powered by electrically-driven motors. These motors, and the electrical leads thereto, often leak allowing the motor or the leads to fail because an electrical short occurs in the wet motor or power lead. Also, it is often difficult to supply electrical power to the mud pit site because of its location away from the drilling rig. In some of the embodiments of the present invention, a pump located on the ground adjacent the edge of the mud pit is utilized.
It is therefore the primary object of the present invention to provide a superior device for increasing the evaporation of liquid from mud pits.
It is another object of the present invention to provide a device for rapidly evaporating a liquid such as water utilizing hollow core spray nozzles for greatly enhancing the evaporation rate of liquid by increasing the area of contact between the liquid by increasing the area of contact between the liquid and atmosphere and without clogging the nozzle orifices.
It is yet another object of the present invention to provide a device which can be floated on and which can rise and fall with the liquid to be evaporated.
It is still another object of the present invention to provide a device which has a collection chamber for settling out and, thus, substantially reducing large particulate matter from exiting the nozzle orifices.
It is a further object of the present invention to provide a device for evaporating liquid which is very efficient, yet relatively inexpensive to construct, operate, and maintain, when compared to devices of the prior art.
It is also another object of the present invention to provide an evaporating device which utilizes a pump located on the ground adjacent the mud pit.
Other and further objects of the present invention will be apparent from the following description and claims, and are illustrated in the accompanying drawings, which, by way of illustration, show preferred embodiments of the present invention and the principles thereof, and what is now considered to be the best mode in which to apply these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departure from the invention.